Bond Graph Modelling of Chemoelectrical Energy Transduction

TL;DR

This paper extends bond graph modelling to include chemoelectrical transduction, enabling thermodynamically consistent analysis of energy consumption in excitable membranes, with applications to healthy and diseased neurons.

Contribution

It introduces a novel energy-based bond graph model for chemoelectrical systems, improving accuracy over proxy methods and applicable to various neuronal conditions.

Findings

Energy consumption during action potentials can be directly computed.

The model differentiates energy use in healthy versus degenerative neurons.

Simulated and in vitro data validate the model's effectiveness.

Abstract

Energy-based bond graph modelling of biomolecular systems is extended to include chemoelectrical trans- duction thus enabling integrated thermodynamically-compliant modelling of chemoelectrical systems in general and excitable membranes in particular. Our general approach is illustrated by recreating a well-known model of an excitable membrane. This model is used to investigate the energy consumed during a membrane action potential thus contributing to the current debate on the trade-off between the speed of an action potential event and energy consumption. The influx of Na+ is often taken as a proxy for energy consumption; in contrast, this paper presents an energy based model of action potentials. As the energy based approach avoids the assumptions underlying the proxy approach it can be directly used to compute energy consumption in both healthy and diseased neurons. These results are illustrated by comparing the energy consumption of healthy and degenerative retinal ganglion cells using both simulated and in vitro data.